Can occur in babies as well as adults and adolescents.
3 - 12% of the population have it; it's common.
Comes in seborrheic distribution - i.e hairy areas.
(scalp, eye brows, peri nasal folds, chest, sub mammary, axillary, peri umbilical, pubic areas)
If severe seborrheic dermatitis, think if immunosuppresion -> HIV
Aetiology unknown -
Otitis externa and blepharitis (crusty eye lids + occular burning / dryness) are common complications of seborrheic dermatitis. - [Source]PassMedicine
Aetiology: incompletely understood; malazzesia proliferation may play a role along with many other risk factors.
Combined hyperlipidaemia
Disorders of chylomicrons and VLDL -
2. commonest - polygenic hypertriglyceridaemia. ("vast majority" of hypertriglyceridaemia patients are polygenic.) Patients have modest elevations in triglycerides.
1. Rarely, severe hypertriglyceridemia is caused by monogenic inheritance. (but not necessarily autosomal dominant)
disorders of LDL -
Heterozygous familial hypercholesterolaemia (HeFH) -
#autosomalDominant
Defective LDL receptor
mild to severe lipid derangement (==1/350== incidence)
Mutations mainly affect the LDLR receptor.
Can have physical signs including xanthomas.
Presents in children.
Also caused by defective LDL receptor.
Poor response to statins.
Liver transplantation can normalize lipid levels. (?introduces hepatocytes with functioning LDL receptors)
Mutations in the apoB and PCSK9 genes - same presentation as HeFH, but milder. Only way to differentiate it genetic tests. - relatively common
Polygenic hypercholesterolaemia - no single identifiable gene deffect but have moderately elevated cholesterol levels.
disorders of HDL - rare
See [[passMedicine Summaries#Evaluation of gradual visual loss]]
[!TIP] Mnemonic: RIFC: retina - ipsi, Field - contra
A particular side of the retina is innervated by the same side of the brain.
This means that a side of the visual field is connected to the contralateral side of the brain
See also:
[!INFO] Retrochiasmal lesions will cause contralateral homonymous visual field defects.
According to the figure above, temporal lobe lesions will cause a contralateral superior quadrantonopia.
These are "Meyer's loop" lesions.
| Hyphema | Retinal detachment |
[!INFO] Visual loss means loss of one or more of
- acuity
- Color vision
- visual field
Central Vs. Peripheral vision loss:
Speed of onset
| Retinal artery occlusion (RAO) | Retinal Venous occlusion (RVO) |
|---|---|
| Less common | Much more common |
| Older population | older population |
| Urgent need of further evaluation | Doesn't need further evaluation for cause |
| Higher risk of ASCVD events | |
| Managed by neurologist - like a stroke | Managed by ophthalmologist |
| Permanent renal death in a few hours. | |
| Commonest causes are emboli: + ICA emobli + aortic arch, cardiac |
|
| Sudden vision loss (curtain coming down) | Vision loss ranges from slight to severe |
| Retinal haemorrhages are common | |
| Vascular causes are the main risk factors | Age seems to be the main risk factor |
| Source |